Fixed stock assembly and method for forming the same

ABSTRACT

Fixed stock assemblies and methods for forming fixed stock assemblies are provided. A fixed stock assembly includes a stock, or stock body, that has a receiver extension cavity extending therethrough and at least one stock stabilizing member. When a conventional carbine/collapsible receiver extension is positioned within the receiver extension cavity, the stock stabilizing member is actuated/adjusted/manipulated to extend into the receiver extension cavity and contact the receiver extension, thus exerting a force on receiver extension and/or a force on the stock. The stock stabilizing member may contact a surface of the receiver extension that is substantially perpendicular to a central axis of the receiver extension cavity and/or the receiver extension. The force on the receiver extension is in a direction away from the lower receiver, and the force on the stock is in a direction towards the lower receiver.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent Application No. 61/822,653, filed May 13, 2013, entitled “Fixed Stock Assembly and Method for Forming the Same,” which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

The present invention relates to stock assemblies for firearms. In particular, the present invention relates to fixed stock assemblies for long guns, such as Stoner-design rifles, and methods for forming such systems.

BACKGROUND

Recent years have seen a significant increase in demand for firearms and firearm-related accessories, for both civilian/recreational and military uses. This increased demand can especially be seen with the increased sales of assault rifles and accessories for use with assault rifles. Some of the most popular assault rifles, for civilian, law enforcement, and military uses, are those based on Eugene Stoner's design (e.g., the M-16/AR-15 and variants thereof, the AR-10 and variants thereof, etc.).

Most Stoner-design rifles manufactured today are equipped with a “collapsible” butt stock, or stock, assembly. That is, the length of the stock assembly is capable of being manually adjusted (i.e., by hand, without tools). Collapsible stock assemblies typically include or utilize a “carbine” receiver extension (or buffer tube) that is fixed to the lower receiver of the rifle using an end plate, which goes on the back end of the lower receiver of the rifle, and a castle nut, which tightens the receiver extension and the end plate to the lower receiver.

However, for various reasons (e.g., personal preference and/or jurisdictional regulations), some Stoner-design rifles are equipped with a “fixed” stock assembly, which is not capable of being adjusted (at least not manually). One example of a fixed stock assembly is the type that is typically found on M16A4 rifles and is often referred to as a “rifle” stock assembly, which utilizes a “rifle” receiver extension that is considerably longer than a carbine receiver extension. Although these stocks are “fixed” in length, some users find them undesirably long, and although they do not utilize an end plate or castle nut, the rifle receiver extension still needs to be properly “torqued” (i.e., tightened) to the lower receiver. This procedure may be difficult for many users, as they may not have access to the proper tools, for example.

In recent years, several fixed stock assemblies have been developed which are closer in length to collapsible stock assemblies (i.e., shorter than rifle stock assemblies). However, some of these fixed stock assemblies require a unique receiver extension, while others use a conventional carbine receiver extension but still require the use of the end plate and/or castle nut, which, similar to rifle receiver extensions, are difficult for many users to install properly, as specialized tools are required.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will hereinafter be described in conjunction with the appended drawing figures, wherein like numerals denote like elements, and in which:

FIG. 1 is a side view of a firearm;

FIG. 2 is an isometric view of a conventional lower receiver for a Stoner-design rifle;

FIG. 3 is a side view of a conventional receiver extension for a collapsible stock assembly for a Stoner-design rifle;

FIG. 4 is a bottom view of the receiver extension of FIG. 3;

FIG. 5 is an end view of the receiver extension taken along line 5-5 in FIG. 3;

FIG. 6 is a cross-sectional view of the receiver extension taken along 6-6 in FIG. 5;

FIG. 7 is an isometric view of a fixed stock according to some embodiments of the present invention;

FIG. 8 is a side view of the fixed stock of FIG. 7;

FIG. 9 is a plan view of a front end of the fixed stock of FIG. 8;

FIG. 10 is a cross-sectional view of the fixed stock taken along line 10-10 in FIG. 9;

FIGS. 11-17 are various views of the fixed stock of FIG. 7 illustrating installation on the lower receiver of FIG. 2 and the receiver extension of FIG. 3;

FIGS. 18 and 19 are side views of the receiver extension of FIG. 3 threaded into the lower receiver of FIG. 2;

FIGS. 20 and 21 are cross-sectional views of a fixed stock according to other embodiments of the present invention;

FIG. 22 is an isometric view of a spacer which may be used in the fixed stock shown in FIGS. 20 and 21; and

FIG. 23 is a side view of a portion of the fixed stock of FIGS. 20 and 21 illustrating the use of the spacer of FIG. 22.

DETAILED DESCRIPTION

The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, and brief summary, or the following detailed description. It should also be noted that FIGS. 1-23 are merely illustrative and may not be drawn to scale.

According to one aspect of the present invention, fixed stock assemblies for Stoner-design rifles are provided. In some embodiments, a fixed stock assembly includes a stock, or stock body, that has a receiver extension cavity extending therethrough and at least one stock stabilizing member extending into the receiver extension cavity. When a conventional carbine/collapsible receiver extension, the front end of which is threaded into a lower receiver for a Stoner-design rifle, is positioned within the receiver extension cavity, the at least one stock stabilizing member is actuated/adjusted/manipulated to extend into the receiver extension cavity and contact the receiver extension, thus exerting a force on receiver extension and/or a force on the stock. The at least one stock stabilizing member may contact a surface of the receiver extension that is substantially perpendicular to a central axis of the receiver extension cavity (and/or the receiver extension). The force on the receiver extension is in a direction away from the lower receiver, and the force on the stock is in a direction towards the lower receiver.

The at least one stock stabilizing member (and/or the force(s) exerted thereby) may be adjusted such that the receiver extension and/or the stock are suitably “locked” or “tightened” into position for use of the stock assembly during use of the respective firearm. As such, the fixed stock assembly allows for the use of a conventional carbine receiver extension without requiring an end plate or castle nut and the tools typically associated with the installation thereof.

FIG. 1 illustrates a firearm, more particularly, a Stoner-design rifle (e.g., an AR-15) 10. Generally, the rifle 10 may be understood to include a lower “half” 12 and an upper half 14. Amongst other components which will be appreciated by those skilled in the art, the lower half 12 includes a lower receiver 16 and a stock assembly 18, and the upper half 14 includes an upper receiver 20 and a barrel assembly 22.

The stock assembly 18 shown in FIG. 1 is an example of a conventional “collapsible” (or “carbine”) stock assembly and includes a carbine receiver extension 24, an end plate 26, a castle nut 28, and a collapsible stock (or butt stock) 30. As is commonly understood, the receiver extension 24 is threaded into the back of the lower receiver 16 and tightened thereto with the castle nut 28, with the end plate 26 being between the castle nut 28 and the lower receiver 16 and having the receiver extension 24 inserted therethrough.

FIG. 2 illustrates a conventional lower receiver 16 for a Stoner-design rifle (e.g., a AR-15) in greater detail. In particular, FIGS. 2-4 illustrate the lower receiver 16 in a “stripped” configuration (i.e., just the lower receiver itself, without any other components installed, such as the pistol grip or other lower receiver parts). The lower receiver 16 has a front end 32 and a back end 34. At the back end 34, the lower receiver includes a receiver extension hole 36, which has an inner surface 38 with a series of threads formed thereon (not shown in FIG. 2). The lower receiver 16 also has a depression 40 formed in the back end 34 thereof, below the receiver extension hole 36.

FIGS. 3-6 illustrate the receiver extension 24 in greater detail. As will be recognized by one skilled in the art, the receiver extension 24 is a conventional receiver extension for collapsible/carbine stock assemblies, as produced by various manufacturers. The receiver extension 24 has a front end 42 and a back end 44. As shown, the receiver extension 24 has a series of threads 46 formed on the outer surface near the front end 42. The receiver extension 24 is substantially hollow and has an opening at the front end 42. The receiver extension 24 also includes a ridge structure 48 extending therefrom (i.e., on a side thereof that is usually considered the bottom or lower side thereof). The forward portion of the ridge structure 48 has an angled surface 50, while the rear portion of the ridge structure 48 is flush with the back end 44 of the receiver extension 24. As shown, the ridge structure 48 also has a depressed channel 52 extending a majority of the length of the ridge structure 48. A series of stock position detents (or depressions) 54 are formed within the channel 52. Of particular interest is that the position detents 54 closest to the back end 44 and the front end 42 of the receiver extension 24 include elongated vertical surfaces 56 that also correspond to the respective ends of the depressed channel 52. The receiver extension 24 may be understood to have a central axis 55 extending through a center of a cavity extending from the opening at the front end 42 to the back end 44. Vertical surfaces 56 may be perpendicular (or orthogonal), or at least substantially so, to the central axis 55.

In some embodiments, the receiver extension 24 is a “mil-spec” receiver extension. Thus, the receiver extension 24 may have a length 56 of approximately 7.25 inches and a diameter 58 of approximately 1.185 inches at the front end 40 (i.e., including the threads 44), but at other portions of the receiver extension (i.e., without the threads 46) the diameter 58 may be, for example, between 1.145 and 1.150 inches (excluding the ridge structure 48). The ridge structure 48 may have a width 60 of, for example, between 0.485 and 0.495 inches. The receiver extension 24 may have of wall thickness 62 of approximately 0.73 inches. However, in some embodiments, the receiver extension 24 may be a “commercial” receiver extension, which as slightly different, but similar, dimensions (e.g., a slightly larger diameter at the portions thereof without the threads 46), as is commonly understood. It should be understood that the fixed stock assembly described below may be sized/shaped to accommodate both mil-spec and commercial receiver extensions, or alternatively, different embodiments of the stock assembly may be made for mil-spec and commercial receiver extensions.

FIGS. 7-10 illustrate a fixed stock 70 according to some embodiments of the present invention. The fixed stock is substantially made of a singular, integral piece of material that forms a stock body with a front end 72, a back end 74, a top side 76, and a bottom side 78. In some embodiments, the stock body is made of a polymer or plastic material, but other materials, such as metals (e.g., aluminum) may be used.

The stock 70 has a substantially elongate shape with a receiver extension cavity (or channel) 80 extending therethrough from the front end 72 (i.e., beginning at an opening at the front end 72) towards the back end 74. In some embodiments, the receiver extension cavity 80 is shaped to have a lower portion 82 such that the receiver extension cavity 80 substantially has the same cross-sectional shape and size as a mil-spec receiver extension (or in some embodiments, a commercial receiver extension). On the front end 72 of the stock 70, an alignment protrusion 84 extends outwards below the opening for the receiver extension cavity 80. In the example shown, the alignment protrusion 84 has a substantially semi-circular shape and may have dimensions (e.g., width, length, depth, etc.) similar to the depression 40 on the back end 34 of the lower receiver 16 (FIG. 2).

Still referring to FIGS. 7-10, the stock 70 includes a ridge 86 extending from the bottom side 78 thereof, which connects to the back end 74 as shown. A series of stock stabilizing member openings 88, 90, and 92 are formed through the bottom side 78 of the stock 70. As shown specifically in FIG. 10, the openings 88, 90, and 92 extend through the stock 70 to the receiver extension cavity 80 (or the lower portion 82 thereof). In some embodiments, the openings 88, 90, and 92 have circular cross-sections and are arranged in the stock 70 such that the central axes 94 thereof are at an angle to a central axis 96 of the receiver extension cavity 80 (and/or of the stock 70 and/or that of the receiver extension 24). In the example shown, the angle between the central axes 94 and the central axis 96 of the receiver extension cavity 96 is approximately 45 degrees. However, in other embodiments, this angle may be any angle between 90 degrees (i.e., perpendicular) and 0 degrees (or essentially parallel) and may vary between the openings 88, 90, and 92. In some embodiments, the angle is any angle between 60 degrees and 30 degrees.

It should noted that the openings 88, 90, and 92 are arranged such that as they extend away from the receiver extension cavity 80, the openings 88, 90, and 92 get closer to the front end 72 of the stock (or conversely, as the openings 88, 90, and 92 extend closer to the receiver extension cavity 80, they get closer to the back end 74 of the stock 70).

Still referring to FIG. 10, a threaded insert (or helical insert) 98 is embedded within each of the openings 88, 90, and 92. The threaded inserts 98 may be made of steel. However, in some embodiments, rather than inserts made from a material different than the stock 70, the threads provided by the inserts 98 may simply be formed in the material of the stock (i.e., the openings 88, 90, and 92 may be “tapped” or otherwise have threads formed therein).

FIGS. 11-17 illustrate the installation of the stock 70. As shown in FIG. 11, the front end 42 of the receiver extension 24 is first threaded into the receiver extension hole 36 of the lower receiver 16. As is commonly understood, the receiver extension 24 is threaded into the lower receiver 16 until the front end 42 is positioned appropriately relative to a buffer detent (not shown) in the lower receiver 16, with the ridge structure 48 on the receiver extension 24 being oriented as shown in FIG. 11 (i.e., facing “down”). It should be noted that in at least some embodiments, the receiver extension 24 is installed without an end plate or castle nut (which are typically used when installing conventional receiver extensions for collapsible/carbine stock assemblies). As such, as installed in FIG. 11, the receiver extension 24 may exhibit some “wobble” or “play” (i.e., the receiver extension is somewhat “loose” after being threaded into the lower receiver 16 without the end plate and castle nut).

As shown in FIGS. 12 and 13, the stock 70 is then slid onto the receiver extension 24 (i.e., the receiver extension 24 fits into the receiver extension cavity 80). Due to the mating between receiver extension 24 and the receiver extension cavity 80 (especially because the ridge structure 48 of the receiver extension 24 fits into the lower portion 82 of the receiver extension cavity 80 as shown in FIG. 13), the stock 70 is substantially prevented from rotating relative to the receiver extension 24. In some embodiments, the receiver extension 24 may fit very tightly into the receiver extension cavity 80, and may even require the use of a hammer or similar tool to tap the stock 70 completely into position.

Referring now to FIGS. 12 and 14, the front end 72 of the stock 70 is pressed against the back end 34 of the lower receiver 16 such that the alignment protrusion 84 on the front end 72 of the stock 70 is inserted into the depression 40 on the back end 34 of the lower receiver 16. Thus, the alignment protrusion 84 mates with the depression 40 to prevent the stock 70 from rotating relative to the lower receiver 16, which in turn prevents the receiver extension 24 from rotating relative to the lower receiver 16 (due to the mating between the receiver extension 24 and the receiver extension cavity 80 in stock 70).

As shown in FIG. 15, after the stock 70 is pressed onto the receiver extension 24, stock stabilizing members are inserted into the openings 88, 90, and 92 in the bottom side 78 of the stock 70 (or alternatively, the stock stabilizing members are previously positioned within the openings 88, 90, and 92). In the example shown, the stock stabilizing members are fasteners 100. Each of the fasteners 100 are threaded into/through the respective threaded insert 98 and into the receiver extension cavity 80 of the stock 70 to press against selected portions of the receiver extension 24 (as dictated by the positioning and orientation of the openings 88, 90, and 92 and threaded inserts 98).

As such, the fasteners 100 (or stock stabilizing members) may be movable between (at least) two positions. In a first position, the fasteners 100 do not extend into the receiver extension cavity 80 such that the receiver extension 24 may be freely inserted into and removed from the receiver extension cavity 80. In the second position, the fasteners 100 extend into the receiver extension cavity 80 such that the receiver extension 24 is prevented from being freely inserted into and removed from the receiver extension cavity 80. More particularly, when the fasteners 100 are moved/adjusted/manipulated into the second position after the receiver extension 24 has been inserted into the receiver extension cavity 80, the fasteners 100 prevent the receiver extension 24 from coming out of the receiver extension cavity 80.

In the depicted embodiment, the fasteners 100 are set screws, but in other embodiments, regular screws or bolts may be used. Further, in yet further embodiments, the stock stabilizing members may take for form of knobs or the like such that they may be manipulated by hand, as opposed to requiring a screw driver, allen key, or socket head driver.

In particular, in the depicted embodiment, the fastener 100 inserted into opening 88 presses against the angled surface 50 of the ridge structure 48 on the receiver extension 24. The fasteners 100 inserted into openings 90 and 92 press against the vertical, side surfaces of the positions detents 54 of the ridge structure 48 (e.g., surface 56). Thus, in some embodiments, the width or diameter of the fasteners 100 may be less than a width of the depressed channel 52. The overall effect of the pressing of the fasteners 100 against the various portions of the receiver extension 24 is to apply opposing forces on the receiver extension 24 and the stock 70. In particular, the receiver extension 24 is pressed (or pulled) away from the lower receiver 16, while the stock is pressed into the lower receiver 16.

As the fasteners 100 are tightened and/or pressed into the receiver extension 24, the force on the receiver extension 24 causes the receiver extension 24 to be “locked” into position, thus eliminating any play or wobble between the receiver extension 24 and the lower receiver 16, by essentially applying a “pulling” force on the receiver extension 24 (i.e., pulling the receiver extension 24 away from the lower receiver 16). As will be appreciated by one skilled in the art, this “locking” is caused by friction and/or interference between the threads 46 on the receiver extension 24 and the threads on the inner surface 38 of the receiver extension hole 36 in the lower receiver 16. It should be noted that the fasteners 100 allow the user to “tune” (or adjust) the amount (or magnitude) of force exerted on the receiver extension 24 and/or the stock 70 (i.e., the more the fasteners 100 are tightened, the greater the force is). This may be helpful in compensating for manufacturing tolerances of the receiver extension 24, the lower receiver 16, and/or the stock 70. Additional stability may be provided by the stock 70 being pressed into the lower receiver 16 combined with the tight fit of the receiver extension 24 within the receiver extension cavity 80.

It should also be noted that, in some embodiments, the force applied to the receiver extension 24 by at least some of the fasteners may be in a direction that is substantially directly away from the lower receiver 16 (and/or substantially parallel to the central axis 96 of the receiver extension channel 80). However, because the fasteners 100 are pressing into the receiver extension 24 in a direction that is not perfectly parallel to axis 96 and/or axis 55, the actual direction in which this force is applied may be at angle, perhaps a small angle (e.g., less than 15 degrees), to axis 96 and/or 55. In some embodiments, this angle may be the same as the angle(s) between the central axes 94 of the openings 88, 90, and 92 and the central axis 96 of the receiver extension cavity 80 (and/or the central axis 55 of the receiver extension 55), as described above. As described below, in at least some embodiments, this may be beneficial.

Referring now to FIG. 16, the fastener 100 inserted through opening 92 presses against the elongated vertical surface 56 of the position detent 54 nearest to the back end 44 of the receiver extension 24. This vertical surface, along with the other vertical surfaces (i.e., inner sides) of the position detents 54 provide surfaces suitable for applying a force to the receiver extension 24 substantially directly (i.e., but perhaps at a slight angle) away from the lower receiver 16. As also shown in FIG. 16, the fasteners 100 may include particular types of tips/ends 102. In FIG. 16, the end 102 of the fastener 100 is rounded. However, other types of ends 102 may be used, such as nylon tips (or tips made of other pliable materials), tapered ends, or conventionally-shaped (e.g., “squared” heads) as is discussed below. It should be noted that some types of ends (e.g., nylon) may help lock the fasteners 100 into position against the receiver extension 24 and/or minimize any damage to (e.g., scratching) the receiver extension 24 (i.e., nylon or rounded ends). In the embodiment shown in FIG. 17 (e.g., the fastener 100 through hole 90), the fastener 100 has a tapered tip.

Referring again to FIG. 15, the lateral positions of the fasteners 100 relative to the receiver extension 24 should be noted. More particularly, it should be noted that both ends of each of the fasteners 100 are laterally positioned between the ends 42 and 44 of the receiver extension 24 (or the ends of the receiver extension cavity 80) and/or that no portion of any of the fasteners 100 extends beyond the back end 44 (or the front end 42) of the receiver extension 24 (or the ends of the receiver extension cavity 80). As such, the fasteners 100 allow the overall length of the stock 70 to remain as short as possible (i.e., given a particular length receiver extension).

Thus, the stock assembly (i.e., the receiver extension 24 and the stock 70) may be installed without the need for an end plate or castle nut, using minimal tools (i.e., the only tool required may be that used to rotate/thread/adjust/tighten/manipulate the fasteners 100 through the threaded inserts 98). More specifically, the stock assembly may be installed without using any gunsmithing tools, such as a vise and a special wrench (as is typically needed to properly install castle nuts), while still utilizing a conventional carbine receiver extension on a Stoner-design rifle with a conventional lower receiver. However, in some embodiments, the stock 70 may be configured to allow for the use of an end plate and/or castle nut (e.g., such as in the case when those components are already installed). In such embodiments, a portion of the stock 70 near the front end 72 may be removable (e.g., a spacer or collar portion) to provide sufficient room for the end plate and/or castle nut.

Additionally, because multiple fasteners 100 are used, at least in some embodiments, to pull the receiver extension 24 away from the lower receiver 16 and/or push the stock 70 into the lower receiver 16, the stock assembly described above provides a level of redundancy not provided by conventional stock assemblies (i.e., collapsible or fixed). That is, in the event that one of the fasteners 100 loosens, or otherwise fails, during use, the remaining fasteners 100 will continue to hold the receiver extension 24 and/or the stock 70 in a suitable position (i.e., the remaining fasteners 100 will continue to exerted the force(s) described above and hold the receiver extension 24 and the stock 70 firm in place). In contrast, conventional stock assemblies may fail (i.e., come loose) if the castle nut loosens (in collapsible stock assemblies) or if the rifle receiver extension loosens from the lower receiver (in rifle stock assemblies).

Referring now to FIG. 18, as described above, when the receiver extension 24 is initially threaded into the receiver extension hole 36 in the lower receiver 36, the receiver extension 24 may “wobble” relative to the lower receiver, as indicated by the arrows shown. As shown in FIG. 19, when the stock 70 (not shown) is installed, and the fasteners 100 are tightened as described above, the receive extension may “cant” (or tilt) within the receiver extension hole 36 due to the fact that the force exerted on the receiver extension 24 may not be in a directly that is perfectly parallel to the central axis 55 of the receiver extension. This is evident in FIG. 19 because of the movement of the central axis 55 shown. This canting/tilting of the receiver extension 24 may actually facilitate the “locking” of the receiver extension 24 relative to the lower receiver 16. More particularly, this canting/tilting may cause a positive engagement between the threads 46 on the receiver extension 24 and the threads on the inner surface 38 of the receiver extension hole 36 with a relatively small force (i.e., at an angle to the central axis 55) being applied on the receiver extension 24.

It should be noted that due to the tolerances typically used when manufacturing receiver extensions 24 and lower receivers 16, this canting/tilting may be relatively minor (e.g., at most a few degrees). Thus, this canting/tilting will not adversely effect the operation of the rifle (e.g., because the bolt carrier of a Stoner-design rifle only extends into the receiver extension 24 a few inches during cycling). As such, in at least some embodiments described herein, this canting/tilting may actually be considered to be beneficial, as it facilitates the “locking” between the receiver extension 24 and the lower receiver 16.

In some embodiments, the stock 70 is sized so that it may be utilized with different types of collapsible/carbine receiver extensions. An example of such an embodiment is shown in FIGS. 20 and 21. In FIG. 20, the stock 70 is utilized with a conventional (e.g., mil-spec) receiver extension 24. However, note that the receiver extension 24 shown in FIG. 20 has six position detents 54, as opposed to four (which is the case with the receiver extension described above). As will be appreciated by one skilled in the art, true “mil-spec” collapsible/carbine receiver extensions 24 usually have four position detents 54. However, some collapsible/carbine receiver extensions 24 have six position detents 54, but are still regarded as “mil-spec” (i.e., such receiver extensions typically have the same overall dimensions as true mil-spec receiver extensions).

Still referring to FIG. 20, note the gap 104 between the end 44 of the receiver extension 24 and the end of the receiver extension cavity 80 in the stock 70. Also note in FIG. 20 that the fastener 100 inserted into opening 88 has a nylon tip, while the others have tapered ends (i.e., in some embodiments, different types of fasteners 100 may be used in the openings 88, 90, and 92).

Referring now to FIG. 21, the stock 70 shown in FIG. 20 is being utilized with a slightly longer collapsible/carbine receiver extension 24, as is evident due to the decreased size of gap 104. An example of such a receiver extension 24 is the A5 receiver extension for the A5 buffer system/stock assembly available from Vltor Weapons Systems of Tucson, Ariz. In some embodiments, the stock 70 is capable of utilizing both conventional collapsible/carbine receiver extensions and receiver extensions with different lengths (such as the A5) with no modifications whatsoever.

However, optionally, an additional opening 106 (which may have a threaded structure therein similar to that described above) is provided in the stock 70 as shown by the dashed lines in FIG. 21. As is evident from the position of opening 106, the opening 106 may be used with the receiver extension 24 shown in FIG. 21 in a manner similar to that of opening 92 when the receiver extension shown in FIG. 20 is utilized. As another option, in some embodiments, a spacer 108 is provided as shown in FIG. 21, which is shown in greater detail in FIGS. 22 and 23. It should be noted that both the additional opening 106 and the spacer 108 are not required, at least in some embodiments, for the stock 70 to accommodate such different types of collapsible/carbine receiver extensions.

Other embodiments may be designed to be compatible with rifles besides Stoner-design rifles (such as AK-47s and variants thereof and the SCAR series of rifles available from FNH USA of Mclean, Va.), which have been modified with a receiver extension similar to receiver extensions for Stoner-design rifles.

It should also be understood that other accessories may be integrated into the fixed stock 70 described above. For example, the fixed stock 70 may also include one or more mechanisms to attach a sling to the stock 70, such as slots (for looping a sling therethrough) and “quick-detach” (QD) sling sockets compatible with QD sling swivels. Additionally, stock extensions and/or butt (or recoil) pads may be provided which can be attached to the back side 74 of the stock 70 to alter the overall length of the stock 70 and/or make the stock 70 more comfortable to use. Likewise, a mechanism may be provided on the stock 70 to effectively make the stock “adjustable” in length (e.g., a slider mechanism in which a portion of the stock 70 may be actuated relative to the main body of the stock 70 to adjust the overall length of the 70). However, in at least some embodiments, the main body of the stock 70 would still remain in a fixed position relative to the receiver extension, in a manner similar to that described above.

Furthermore, the overall shape of the stock 70 may be changed to provide a different overall “feel” to the user, such as providing more or less area on the top side 76 for a “cheek weld,” as is commonly understood.

Thus, according to one aspect of the present invention, a fixed stock for Stoner-design rifles is provided. The fixed stock includes a stock body with a receiver extension cavity formed therein. The receiver extension cavity extends from a receiver extension opening at the front end of the stock body towards the back end of the stock body. The stock body also includes at least one stock stabilizing member movable between a first position and a second position. When the (at least one) stock stabilizing member is in the first position, the stock stabilizing member does not prevent a carbine receiver extension from being inserted into and removed from the receiver extension cavity. When the stock stabilizing member is in the second position, the stock stabilizing member prevents the carbine receiver extension from being inserted into and/or removed from the receiver extension cavity.

When a carbine receiver extension is positioned within the receiver extension cavity and the stock stabilizing member is moved from the first position into the second position, the stock stabilizing member exerts (or applies) a force onto the receiver extension and/or the stock body. When a front end of the receiver extension is threaded into a lower receiver of a Stoner-design rifle, the front end of the stock body contacts the lower receiver, and the force exerted on the receiver extension is in a direction away from the lower receiver while the force exerted on the stock body is in a direction towards the lower receiver, causing the stock body to press against the lower receiver.

In some embodiments, when the receiver extension is positioned with the receiver extension cavity and the stock stabilizing member is in the second position, the stock stabilizing member contacts a surface of the receiver extension that is substantially perpendicular to a central axis of the receiver extension cavity (and/or the receiver extension).

In some embodiments, the stock body includes a plurality of stock stabilizing members. When the front end of the receiver extension is threaded into the lower receiver, the receiver extension is positioned with the receiver extension cavity, and each of the stock stabilizing members are in the second position, each of the stock stabilizing members exert a force on the receiver extension in a direction away from the lower receiver and a force on the stock body in a direction towards the lower receiver.

In some embodiments, the stock stabilizing members are fasteners (e.g., threaded members) inserted through stock stabilizing member openings extending from a side (e.g., bottom side) of the stock body into the receiver extension cavity. The stock body may also include a threaded structure (e.g., a threaded insert or helical insert) positioned adjacent to each of the stock stabilizing member openings such that each the fasteners is threaded through a respective one of the threaded structures.

In some embodiments, a fixed stock for Stoner-design rifles is provided. The fixed stock includes a stock body with a receiver extension cavity formed therein. The receiver extension cavity extends from a receiver extension opening at the front end of the stock body towards the back end of the stock body. At least one stock stabilizing member is coupled to the stock body and movable between a first position and a second position. When the at least one stock stabilizing member is in the first position, the stock stabilizing member does not prevent a carbine receiver extension from being inserted into and removed from the receiver extension cavity, and when the stock stabilizing member is in the second position, the stock stabilizing member prevents the carbine receiver extension from being inserted into and/or removed from the receiver extension cavity. When a carbine receiver extension, having a front end and a back end, is positioned within the receiver extension cavity and the at least one stock stabilizing member is moved from the first position into the second position, the stock stabilizing member exerts a force onto the receiver extension and the stock body so that when the front end of the receiver extension is threaded into a lower receiver of a Stoner-design rifle, the front end of the stock body contacts the lower receiver, and the force exerted on the receiver extension is in a direction away from the lower receiver while the force exerted on the stock body is in a direction towards the lower receiver, causing the stock body to press against the lower receiver. When the carbine receiver extension is positioned within the receiver extension cavity and the at least one stock stabilizing member is in the second position, all of the at least one stock stabilizing member is laterally positioned between the front end of the receiver extension and the back end of the receiver extension.

While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the invention as set forth in the appended claims and the legal equivalents thereof. 

We claim:
 1. A fixed stock for Stoner-design rifles, the fixed stock comprising: a stock body with a receiver extension cavity formed therein, the receiver extension cavity extending from a receiver extension opening at the front end of the stock body towards the back end of the stock body; and at least one stock stabilizing member coupled to the stock body and movable between a first position and a second position, wherein when the at least one stock stabilizing member is in the first position, the stock stabilizing member does not prevent a carbine receiver extension from being inserted into and removed from the receiver extension cavity, and when the stock stabilizing member is in the second position, the stock stabilizing member prevents the carbine receiver extension from being inserted into and/or removed from the receiver extension cavity, wherein when a carbine receiver extension, having a front end and a back end, is positioned within the receiver extension cavity and the at least one stock stabilizing member is moved from the first position into the second position, the stock stabilizing member exerts a force onto the receiver extension and the stock body so that when the front end of the receiver extension is threaded into a lower receiver of a Stoner-design rifle, the front end of the stock body contacts the lower receiver, and the force exerted on the receiver extension is in a direction away from the lower receiver while the force exerted on the stock body is in a direction towards the lower receiver, causing the stock body to press against the lower receiver, and wherein when the carbine receiver extension is positioned within the receiver extension cavity and the at least one stock stabilizing member is in the second position, all of the at least one stock stabilizing member is laterally positioned between the front end of the receiver extension and the back end of the receiver extension.
 2. The fixed stock of claim 1, wherein the carbine receiver extension has a central axis, and where the force exerted on the carbine receiver extension is in a direction that is not parallel to the central axis of the carbine receiver extension.
 3. The fixed stock of claim 2, wherein the at least one stock stabilizing member is coupled to the stock body such that the magnitude of the force exerted on the carbine receiver is adjustable.
 4. The fixed stock of claim 3, wherein the when the at least one stock stabilizing member is in the second position, the at least one stock stabilizing member contacts a surface of the carbine receiver extension which is substantially perpendicular to the central axis of the carbine receiver extension.
 5. The fixed stock of claim 4, wherein the surface of the carbine receiver extension which is substantially perpendicular to the central axis of the carbine receiver extension forms a side of a position detent on the carbine receiver extension.
 6. The fixed stock of claim 5, wherein the at least one stock stabilizing member is coupled to the stock body such that rotation of the at least one stock stabilizing member causes the at least one stock stabilizing member to extend into the receiver extension cavity.
 7. The fixed stock of claim 6, wherein an end of the at least one stock stabilizing member which contacts the surface of the carbine receiver extension is rounded or tapered.
 8. The fixed stock of claim 6, wherein an end of the at least one stock stabilizing member which contacts the surface of the carbine receiver extension is made of nylon.
 9. A fixed stock for Stoner-design rifles, the fixed stock comprising: a stock body with a receiver extension cavity formed therein, the receiver extension cavity extending from a receiver extension opening at the front end of the stock body towards the back end of the stock body; and at least one stock stabilizing member coupled to the stock body and movable between a first position and a second position, wherein when the at least one stock stabilizing member is in the first position, the stock stabilizing member does not prevent a carbine receiver extension from being inserted into and removed from the receiver extension cavity, and when the stock stabilizing member is in the second position, the stock stabilizing member prevents the carbine receiver extension from being inserted into and/or removed from the receiver extension cavity, wherein when a carbine receiver extension, having a front end and a back end, is positioned within the receiver extension cavity and the at least one stock stabilizing member is moved from the first position into the second position, the stock stabilizing member exerts a force onto the receiver extension and the stock body so that when the front end of the receiver extension is threaded into a lower receiver of a Stoner-design rifle, the front end of the stock body contacts the lower receiver, and the force exerted on the receiver extension is in a direction away from the lower receiver while the force exerted on the stock body is in a direction towards the lower receiver, causing the stock body to press against the lower receiver, wherein when the carbine receiver extension is positioned within the receiver extension cavity and the at least one stock stabilizing member is in the second position, all of the at least one stock stabilizing member is laterally positioned between the front end of the receiver extension and the back end of the receiver extension, and wherein the at least one stock stabilizing member is coupled to the stock body such that rotation of the at least one stock stabilizing member causes the magnitude of the force exerted on the carbine receiver to be adjusted.
 10. The fixed stock of claim 9, wherein the carbine receiver extension has a central axis, and where the force exerted on the carbine receiver extension is in a direction that is not parallel to the central axis of the carbine receiver extension.
 11. The fixed stock of claim 9, wherein when the at least one stock stabilizing member is in the second position, the at least one stock stabilizing member contacts a surface of the carbine receiver extension which is substantially perpendicular to the central axis of the carbine receiver extension.
 12. The fixed stock of claim 11, wherein the surface of the carbine receiver extension which is substantially perpendicular to the central axis of the carbine receiver extension forms a side of a position detent on the carbine receiver extension.
 13. The fixed stock of claim 9, wherein the at least one stock stabilizing member is coupled to the stock body such that rotation of the at least one stock stabilizing member causes the at least one stock stabilizing member to extend into the receiver extension cavity.
 14. The fixed stock of claim 13, wherein an end of the at least one stock stabilizing member which contacts the surface of the carbine receiver extension is rounded or tapered.
 15. The fixed stock of claim 14, wherein an end of the at least one stock stabilizing member which contacts the surface of the carbine receiver extension is made of nylon.
 16. A fixed stock for Stoner-design rifles, the fixed stock comprising: a stock body with a receiver extension cavity formed therein, the receiver extension cavity extending from a receiver extension opening at the front end of the stock body towards the back end of the stock body; and at least one stock stabilizing member coupled to the stock body and movable between a first position and a second position, wherein when the at least one stock stabilizing member is in the first position, the stock stabilizing member does not prevent a carbine receiver extension from being inserted into and removed from the receiver extension cavity, and when the stock stabilizing member is in the second position, the stock stabilizing member prevents the carbine receiver extension from being inserted into and/or removed from the receiver extension cavity, wherein when a carbine receiver extension, having a front end and a back end, is positioned within the receiver extension cavity and the at least one stock stabilizing member is moved from the first position into the second position, the stock stabilizing member exerts a force onto a surface of the receiver extension that is substantially perpendicular to a central axis of the receiver extension and the stock body so that when the front end of the receiver extension is threaded into a lower receiver of a Stoner-design rifle, the front end of the stock body contacts the lower receiver, and the force exerted on the receiver extension is in a direction away from the lower receiver while the force exerted on the stock body is in a direction towards the lower receiver, causing the stock body to press against the lower receiver, wherein when the carbine receiver extension is positioned within the receiver extension cavity and the at least one stock stabilizing member is in the second position, all of the at least one stock stabilizing member is laterally positioned between the front end of the receiver extension and the back end of the receiver extension, and wherein the at least one stock stabilizing member is coupled to the stock body such that rotation of the at least one stock stabilizing member causes the magnitude of the force exerted on the carbine receiver to be adjusted. 